Hello @Alexxis_04
I hope you are doing very well.
Apologies for the long delay.
It appears, yes, the IRQSTEER should be configured.
Please take a look t the lpuart_edma_transfer.c of SDK 2.9.0:
/* Enable interrupt in irqsteer */
IRQSTEER_Init(IRQSTEER);
IRQSTEER_EnableInterrupt(IRQSTEER, ADMA_UART0_DMA_RX_INT_IRQn);
IRQSTEER_EnableInterrupt(IRQSTEER, ADMA_UART0_DMA_TX_INT_IRQn);
Also, keep in mind that Receive Data Register Full Flag behavior:

So, you can try to disable the FIFO or set the Watermark to 0.
I hope this information can helps to you.
Best regards,
Salas.